Feed chucks

ABSTRACT

A feed chuck for a machine tool including a tubular body member, a plurality of radially spaced, longitudinally extending slots in said body member, spring means in each of the slots each having one end fixed in an end of its slot and having its middle portion bowed inwardly of the body member for engagement with bar stock, movable spring compression adjusting means engaging the body member and engaging the other ends of the spring means for further inwardly bowing each of the spring means to various positions for adjusting the gripping force on the bar stock inserted into the chuck, a plurality of notches formed in the movable spring compression adjusting means, lock means secured to the body member and engaging at least one of the notches for preventing relative rotation of the body member and the movable spring compression adjusting means, and the lock means having a substantial portion outwardly of the surface of the bowed middle portion of the spring means and between the ends of the spring means.

United States Patent Parsons et al.

15] 3,56,772 451 Apr. 18, 1972 [54] FEED CHUCKS [72] Inventors: Hubert J. Parsons, l-lorseheads; Anders Adolf Peterson, Elmira, both of N.Y.

[73] Assignee: Hardinge Brothers, Inc., Elmira, N.Y.

[22] Filed: Aug. 3, 1970 [211 App]. No.: 60,352

Primary Examiner-Francis S. l-lusar Attorney-Shlesinger, Arkwright & Garvey [5 7] ABSTRACT A feed chuck for a machine tool including a tubular body member, a plurality of radially spaced, longitudinally extending slots in said body member, spring means in each of the slots each having one end fixed in an end of its slot and having its middle portion bowed inwardly of the body member for engagement with bar stock, movable spring compression adjusting means engaging the body member and engaging the other ends of the spring meansfor further inwardly bowing each of the spring means to various positions for adjusting the gripping force on the bar stock inserted into the chuck, a plurality of notches formed in the movable spring compression adjusting means, lock means secured to the body member and engaging at least one of the notches for preventing relative rotation of the body member and the movable spring compression adjusting means, and the lock means having a substantial portion outwardly of the surface of the bowed middle portion of the spring means and between the ends of the spring means.

16 Claims, 12 Drawing Figures PATENTEDAPR 181972 3,656,772

sum 1 UF 2 L'ITH V INVENTORS HUBE/PT' J. PARSONS BY ANDERS A. PETERSON WW' W PATENTED APR 18 1912 F .7] 60/ J INVENTORS- HUBERT J. PARSONS BY ANDERS A. PETERSON FEED crwcxs BACKGROUND AND OBJECTS This invention relates to an improved feed chuck, and more particularly, to the provision of means for locking the tension setting on feed chucks.

This invention is an improvement over Parsons US. Pat. Nos. 2,786,687 issued Mar. 26, 1957 and 2,866,648 issued Dec. 30, 1958 and U.S. Pat. No. to Peterson 2,845,274 issued July 29, 1958.

US. Pat. Nos. 2,786,687, 2,845,274 and 2,866,648, all disclose feed chucks of the kind commonly used for advancing bar stock in automatic screw machines, lathes, or the like, These chucks comprise a generally tubular body member having a plurality of radially spaced, longitudinally extending slots in one end of the chuck. Disposed within the slots are spring members-having a central portion which is bowed inwardly. The central portions of the springs contact the bar stock. One end of the springs is secured to the closed end of the slots in the body of the chuck, and the other end of the spring extends toward the opened end of the slots. A sleeve or cap member having internal threads is screwed onto the body of the chuck and contacts the end of the spring members. Upon continued screwing of the sleeve or cap member, the spring members are bowed inwardly so as to firmly grip the bar stock. The threaded adjustment is provided so as to compensate for wear and to allow the gripping force on the bar stock to be adjusted.

One of the difliculties encountered with this type of chuck is that during rotation of the chuck while on the machine tool spindle, the sleeve or cap member would tend to unscrew from the tubular body of the chuck, and accordingly, the gripping force on the bar stock would be diminished. Prior art attempts to overcome this disadvantage have included the use of lefthanded male threads on the body of the chuck, however, when the rotation of the machine spindle was reversed, the same problem was encountered.

Another prior art attempt at overcoming this disadvantage included providing a plastic insert within the peripheral surface of the sleeve or cap member which would bear against the tubular body of the chuck thread in order to lock the cap in place.

Accordingly, it is a primary object of this invention to overcome the disadvantages of prior art feed chucks.

Another object of this invention is to provide a feed chuck having means for positively securing the work gripping force applied to the bar stock.

Still a further object of this invention is to provide a machine tool feed chuck having means for locking the spring tension settings at a variety of difierent positions.

Still another object of this invention is to provide a lock for the spring compression adjusting means which may be readily adjusted.

These and other objects and advantages of this invention will become apparent when considered in light of the following description and claims when taken together with the drawings in which:

FIG. 1 is a side elevation view of the preferred embodiment of this invention;

FIG. 2 is an exploded fragmentary view with the cap member removed;

FIG. 3 is a view along lines 33 of FIG. 1 and viewed in the direction of the arrows;

FIG. 4 is a view along the lines 4-4 of FIG. 1 and viewed in the direction of the arrows;

FIG. 5 is a perspective view of the cap locking member used in the preferred embodiment of this invention;

FIG. 6 is a side elevation view of an alternate embodiment of this invention;

FIG. 7 is a fragmentary sectional view along lines 77 of FIG. 6 and viewed in the direction of the arrows;

FIG. 8 is a view along lines 8-8 of FIG. 6 and viewed in the direction of the arrows;

FIG. 9 is a view along lines 9-9 of FIG. 6 andviewed in the direction of the arrows;

FIG. 10 is a perspective view of the cap locking member utilized in the alternate embodiment shown in FIG. 6;

FIG. 11 is a perspective view of an alternate cap locking member, and

, FIG. 12 is a fragmentary elevation showing the cap locking member of FIG. 11 in position.

' Referring now to FIG. 1, the chuck generally designated 10 x is shown, having a threaded end 12 for attachment to a machine tool feed tube (not shown). The chuck 10 has a plurality of radially spaced, longitudinally extending slots 14 in which are disposed spring members 16. Springs 16 are secured in the closed end of slots 14 by means of furcations 18 which straddle a portion of the chuck body 10. Springs 16 are of the type disclosed in US. Pat. No. 2,866,648.

The central portion of springs 16 is bowed inwardly so as to contact the bar stock W, and the other end of spring 16 is positioned in a recess 20 in chuck 10. The right end of the chuck 10 as seen in FIG. 2 has male threads 22 formed thereon.

As seen in FIGS. 1, 2 and 4, a sleeve or cap member 24 is provided, and has female threads 26 formed on the interior surface thereof. Male threads 22 and female threads 26 are 1 alike in order that cap 24 may threadedly engage chuck 10. Cap 24 has a plurality of notches 28 formed in its left face as seen in the drawings.

An annular groove 30 is formed in the body of chuck It), as is a groove 32 which extends at right angles to groove 38.

Referring now to FIG. 5, a split ring spring clip 34 is shown, and includes a first projection 36 and a second projection 38. Clip 34 is of a width enabling it to fit within the groove 30 in chuck 10, and projection 36 is of a width permitting it to rest within the groove 32 in chuck 10. Projection 38 is of a width enabling it to fit into any of the notches 28 in cap 24, and is of a length enabling it to extend into notches 28 at a number of 1, different positions in cap 24, as cap 24 may be threaded onto or off of chuck 10.

When it is desired to change the bar stock gripping force of springs 16, a screwdriver or other suitable tool (not shown) is inserted into the space 40 and the open end of clip 34 is lifted raising the projection 38 out of the notch 28. At the same time the clip 34 can then be rotated in the annular groove 30 for a 5 slight distance. This allows the projection 36 to rest on the ad- 5 the body of chuck 10 by merely lengthening the projections 36 and 38, it is preferable that it be located between the ends of springs 16, and close to the cap 24 so as to provide the most rigidity in the locking device.

Referring now to FIG. 6, an alternate embodiment is shown for locking the cap 24. A hole 42 is drilled in the body of chuck l0, and is counterbored as at 44. The recessed area 46 is milled in the body of chuck 10, and a flat surface 48 is milled in chuck 10. Additionally, a notch 50 is provided at the right end of chuck 10. The piece of spring wire 52 is bent to the shape shown in FIG. 10 and is secured to chuck 10 by a rivet 54 passing through the loop 56 of wire 52 and hole 42 in chuck 10. The wire 52 extends towards the cap member 24, passing through the notch 50 of chuck 10 and into one of the notches 28 in cap 24.

The operation of this embodiment is similar to that of the preferred embodiment, in that a screw driver or other suitable tool (not shown) is inserted under the wire 52 in the flat area 48. The wire is lifted out of the notches 28 and 50 enabling the cap 24 to be rotated to adjust the bar stock gripping pressure applied through springs 16. The end wire 52 can also be moved sidewise allowing it to rest on the adjacent shoulder of the body allowing the use of both hands for repositioning the cap 24. After the desired setting is achieved, the wire 52 is released, and it drops into the notch 50 and one of the notches 28 to securely lock the cap 24 in place.

FIGS. 11 and 12 show another embodiment of this invention wherein a clip 60 is formed of a piece of wire bent to the shape shown in FIG. 11 and heat-treated. Clip 60 has a radially inward projection 62 and a longitudinally extending projection 64.

In use, clip 60 rests in annular groove 66 in chuck body 10, and projection 62 is inserted in slot 14 in chuck 10 for holding clip 60 in position. Projection 64 extends into one of the notches 28 for securely locking cap 24 in place. Projection 64 may be lifted out of notch 28 and rotated slightly in groove 66 allowing projection 64 to rest on the chuck body 10 in the manner of the other two embodiments when the cap 24 is being adjusted.

As the cap 24 always tends to loosen when in operation, the clip 60 is' made to bear against the solid side of slot 14 when the cap 24 rotates in a loosening direction. In the drawing, the cap 24 would have a left-hand thread so that if it tried to loosen, it would push projection 64 against the solid wall of slot 14 rather than into the open portion of slot 24 which would bend projection 64. If the cap 24 were right-hand threaded, the clip 60 would have projection 64 on the opposite side to achieve the same'result.

While this invention has been described, it will be understood that it is capable of further modification, and this application is intended to cover any variations, uses and/or adaptations of the invention following in general, the principle of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains, and as may be applied to the essential features hereinbefore set forth, as fall within the scope of the invention or the limits of the appended claims.

We claim:

l. A feed chuck for machine tools including:

a. a tubular body member,

b. a plurality of radially spaced longitudinally extending slots in said body member,

c. spring means in each of said slots each having one end fixed in an end of its slot and having its middle portion bowed inwardly of said body member for engagement with bar stock,

d. movable spring compression adjusting means engaging said body member and engaging the other ends of said spring means for further inwardly bowing each of said spring means to various positions for adjusting the gripping force on bar stock inserted into said chuck,

' e. a plurality of notches formed in said movable spring compression adjusting means,

f. lock means secured to said body member and engaging at least one of said notches for preventing relative rotation of said body member and said movable spring compres sion adjusting means, and

g. said lock means having a substantial portion positioned outwardly of the surface of said bowed middle portion of said spring means and between the ends of said spring means.

2. A feed chuck for machine tools as in claim 1 and wherein:

a. said lock means includes a body portion and a member projecting from said body portion toward said spring compression adjusting means and said projecting member including a portion extending removably and selectively into said at least one of said notches when said spring a. said lock means includes a split rigg, and b. anann arrecessformedmsai tubularbodymember for receiving said split ring. 5. A feed chuck for machine tools as in claim 4 and includa. a notch formed in said tubular body member,

b. said projecting member including a first projection. en-

gaging said notch formed in said tubular body member, and

c. a second projection engaging said notches in said movable spring compression adjusting means.

6. A feed chuckfor machine tools as in claim 5 and wherein:

a. said second projection extends from said first projection.

7. A feed chuck for machine tools as in claim 3 and wherein:

a. said lock means includes a spring wire secured at one end to said tubular body member.

8. A feed chuck for machine tools as in claim 7 and wherein:

a. said spring wire includes a circular portion at one end of said spring wire, and

b. a straight portion extending from said circular portion.

9. A feed chuck for machine tools as in claim 8 and includa. fastening means passing through said tubular body member for securing said spring wire to said tubular body member.

10. A feed chuck for machine tools as in claim 9 and includmg:

a. a notch formed in said tubular body member, and

b. said straight portion of said spring wire passing through saidnotch in said tubular body member.

11. A feed chuck for machine tools as in claim 10 and including:

a. recess means formed in said tubular body member beneath said straight portion of said spring wire for insertion of a tool for lifting said spring wire out of said notch in said movable spring compression adjusting means.

12. A feed chuck for machine tools as in claim 6 and wherein:

a. said first and second projections extend at right angles from said split ring.

13. A feed chuck for machine tools as in claim 12 and including:

a. recess means formed in said tubular body member beneath said projecting member for insertion of a tool for lifting said spring wire out of said movable spring compression adjusting means.

14. A feed chuck for machine tools as in claim 4 and includa. a radially inward projection formed on said split ring for engaging one wall of one of said slots for positioning said split ring on said tubular body member.

15. A feed chuck for machine tools as in claim 14 and wherein:

a. said radially inward projection is formed at one end of said split ring.

16. A feed chuck for machine tools as in claim 15 and wherein:

a. said radially inward projection is substantially perpendicular to said projecting member. 

1. A feed chuck for machine tools including: a. a tubular body member, b. a plurality of radially spaced longitudinally extending slots in said body member, c. spring means in each of said slots each having one end fixed in an end of its slot and having its middle portion bowed inwardly of said body member for engagement with bar stock, d. movable spring compression adjusting means engaging said body member and engaging the other ends of said spring means for further inwardly bowing each of said spring means to various positions for adjusting the gripping force on bar stock inserted into said chuck, e. a plurality of notches formed in said movable spring compression adjusting means, f. lock means secured to said body member and engaging at least one of said notches for preventing relative rotation of said body member and said movable spring compression adjusting means, and g. said lock means having a substantial portion positioned outwardly of the surface of said bowed middle portion of said spring means and between the ends of said spring means.
 2. A feed chuck for machine tools as in claim 1 and wherein: a. said lock means includes a body portion and a member projecting from said body portion toward said spring compression adjusting means and said projecting member including a portion extending removably and selectively into said at least one of said notches when said spring means has been further bowed to lock said springing means to the adjusted gripping position.
 3. A feed chuck for machine tools as in claim 2 and wherein: a. said body portion and said projecting member are formed of resilient material.
 4. A feed chuck for machine tools as in claim 3 and wherein: a. said lock means includes a split ring, and b. an annular recess formed in said tubular body member for receiving said split ring.
 5. A feed chuck for machine tools as in claim 4 and including: a. a notch formed in said tubular body member, b. said projecting member including a first projection engaging said notch formed in said tubular body member, and c. a second projection engaging said notches in said movable spring compression adjusting means.
 6. A feed chuck for machine tools as in claim 5 and wherein: a. said second projection extends from said first projection.
 7. A feed chuck for machine tools as in claim 3 and wherein: a. said lock means includes a spring wire secured at one end to said tubular body member.
 8. A feed chuck for machine tools as in claim 7 and wherein: a. said spring wire includes a circular portion at one end of said spring wire, and b. a straight portion extending from said circular portion.
 9. A feed chuck for machine tools as in claim 8 and including: a. fastening means passing through said tubular body member for securing said spring wire to said tubular body member.
 10. A feed chuck for machine tools as in claim 9 and including: a. a notch formed in said tubular body member, and b. said straight portion of said spring wire passing through said notch in said tubular body member.
 11. A feed chuck for machine tools as in claim 10 and including: a. recess means formed in said tubular body member beneath said straight portion of said spring wire for insertion of a tool for lifting said spring wire out of said notch in said movable spring compression adjusting means.
 12. A feed chuck for machine tools as in claim 6 and wherein: a. said first and second projections extend at right angles from said split ring.
 13. A feed chuck for machine tools as in claim 12 and including: a. recess means formed in said tubular body member beneath said projecting member for insertion of a tool for lifting said spring wire out of said movable spring compression adjusting means.
 14. A feed chuck for machine tools as in claim 4 and including: a. a radially inward projection formed on said split ring for engaging one wall of one of said slots for positioning said split ring on said tubular body member.
 15. A feed chuck for machine tools as in claim 14 and wherein: a. said radially inward projection is formed at one end of said split ring.
 16. A feed chuck for machine tools as in claim 15 and wherein: a. said radially inward projection is substantially perpendicular to said projecting member. 